The present invention relates to automotive vehicle seating and, more particularly, to automotive vehicle seats equipped with manual four-way adjustment assemblies.
Traditionally, only expensive luxury type vehicles have been equipped with seating that is adjustable in multiple directions in addition to fore and aft. Recent consumer demand, however, has made it increasingly important for automobile manufacturers to offer enhanced seat adjustment capability on less expensive vehicles. The cost and weight penalties associated with conventional power seat adjustment systems makes their application in smaller, less expensive vehicles impractical. Accordingly, the use of manual seat adjustment mechanisms is dictated for such applications.
Many different manual seat adjustment mechanisms have been proposed. However, there remains a need for a manual seat adjustment mechanism that is relatively simple in design and construction and therefore inexpensive to manufacture, is durable, and yet is light in weight, quiet, and easy to operate.
It is the primary object of the present invention to provide a four-way manual seat adjustment assembly that satisfies these criteria. In particular, the present invention discloses an improved mechanism for manually adjusting the position of a vehicle seat in either the up and down directions or the fore and aft directions. The present invention, in general, comprises a pair of stationary tracks defining a substantially horizontal plane. Elongated carriages are slidably coupled with the tracks and move longitudinally thereon. A mechanism is coupled with the tracks and carriages which enables selective movement of the carriages longitudinally along the tracks. Also, a vertical adjustment mechanism is provided that is coupled with the seat assembly to enable vertical adjustment of the seat assembly.
The vertical adjustment mechanism includes a pair of quadrants or lift links that are rotatably journalled to the seat frame members fastened to the underside of the seat bottom. The seat frame members are pivotably mounted at their rearward end to the carriages. A pair of pivot pins is fixedly attached to the quadrants/lift links and journalled to a pair of brackets that is in turn slidably mounted to the forward ends of the carriages. Vertical movement of the seat frame members relative to the carriages raises and lowers the pivot point of the quadrants/lift links, thereby causing the quadrants/lift links to rotate. The slidable mounting brackets take up the horizontal movement of the pivot pins as the quadrants rotate. A locking mechanism including a pawl that is engagable with teeth on the quadrants is provided to secure the seat frame in a selected vertical position. In addition, plastic bushings are provided at each of the various pivot points in the preferred embodiment to provide smoothness of operation and to minimize the amount of noise generated by the mechanism when operated.
From the following specification in connection with the accompanying drawings, other objects and advantages of the present invention will become apparent to those skilled in the art.